Ghosts of Mars may not be one of John Carpenter's finer efforts, but you can't knock the veteran director for staying true to his roots--it's clearly a Carpenter film, reveling in its B-movie blood lust, and fueled by the director's rock & roll rebellion as well as the sex appeal of star Natasha Henstridge. This rickety sci-fi/horror hybrid recalls Carpenter's Assault on Precinct 13, with various connections from throughout the director's career--for better and worse. It's the year 2176, and human colonists on Mars are controlled by a political "matronage," with women (for reasons unexplained) holding court in the capitol city of Chryse. Mars Police Force Lt. Ballard (Henstridge) has been sent to retrieve James "Desolation" Williams (Ice Cube), the planet's most notorious criminal, from a remote mining-colony prison. With her ill-fated crew, Ballard discovers that the colonists have nearly all been possessed by ancient Martian spirits bent on reclaiming the planet, turning them into an army of self-mutilating freaks suggesting an unholy union of Marilyn Manson and the sadomasochistic Cenobites from the Hellraiser films. None of this makes much sense, and the shaky alliance between cops and criminals is a predictable excuse for rampant battle scenes between surviving humans and the ghost-possessed maniacs. Exotic weaponry abounds (along with cheap special effects and some laughable dialogue), resulting in the gruesome dispatch of expendable costars Pam Grier, Joanna Cassidy, Robert Carradine, and Clea Duvall. Driven by Carpenter's synth-metal score, this violent free-for-all has a few brief highlights, but it's suspenseless and ultimately absurd. It's not much, but for loyal fans it's probably enough. --Jeff Shannon